John gkrant



' May 26, 1931. J. GRANT 1,806,625

HOLD-DOWN SLEEVE FOR EXPANSIVE REAIEBS Filed March 7. 1930 29 andcontraction.

Patented Mayas, 193.1Y if 1P Meer JOHN GRANT, l"or Los ANGELES,@anteprima f HOLD Down SLEEVE .ronnxrnnsivn -REaMERs y Application filedMarch v1'?,

expansive reamer.

'Although the invention is notv limited to any particular form ofexpansive'reamer or 10 underreamer, it Will .bestbe understood in itsgeneral ch/araoteristios, principal" and scope from a Consideration ofspecific appliation of an illustrative' embodimenttoa particu lar `typefof expansive imderreamer.Y That l5 selected type ofexpansive'underreamer inl.

volves a tubular slotted Vbody andan internal` cutter 'abutment yCore ormandrel the cutters being` held in .the body slots vand riding up anddovvnthe internal mandrel for expansion The internal mandrel is soformed thatlwhen the cutters move up- Wardly'they move outwardly toexpanded position. By holding thecutters dovvn they can f. be preventedV:trom movingoutvvardlyin vex- ;25 pansion; and the expansiveunderreame'r is thus Vtransformed 'into a Vnonexpansive' plain reamerhaving a .reaming diameter'equal to the Acontracted 'diameter of thefexpansivie reamer.

' "'30 behold-down gurie-"which isfapeiifea te this vparticular type ofreame'r alsohas-pr visionior positively holding the "cutters 'iinvvardlyando-r preventing their loose out- Ward movement; andV when held intheir in-f "35 ner contracted positions, thestructure is such that thecutters bear inwardly l against the' internal abutment mandrel and ialsoV bear inwardly 'against eaeh other. The resulltinQ structuralarrangement isthus of lvgreat solide ity and-strength. Y

VThe ,invent'on `in its various aspects Will.

new be best understood lfrom adetaliled and specific description of thechosenfillustrative 45 embodimengas applied tothe particular itype 4 ofexpansive underreamerchosen as an illus-v tra-tion of the applicabilityof myfinvention. For this purpose referenee lishad'toftheaccompanying'dravvings in which:

' Wardly tap ered portion f Then a ,mandrel 1930. semaine. 434,020.

showing `an Y underreamer of V said equipped Withmy preseiijtnventionf;

Fig; 2 is asimilar sect' on shovving'thejsaine underreamer with the'hld-fdown sleeve lr e moved,` and/With l'the "underrea'nier in "eXpand- "l edrstem" Y Y Fig`. 3 vis 'an enlarged erossfseietion on vlineSfeer-rig. 1; i

Fig. l1' is an enlarged cross section on line 0f 1'5- f ,60 Fig. i5;V isa 'detail'-jelevati'onr'df a mo'difed form of hold-down sleeve, i

In .the dlWii-lgsthjet underreamer is'illu'sI'- a -3 i at landUhflQfII-gitudin'al'ly extending body 4's lo'ts 'at r111; "In t'he jparticularl'underrreamer illustrated 1there' are three eireumferentiallyequidistaht T bo'dyslots; vbut this number', which is equalt'o theynumber of Y'the outtersemployed, mayfloevaredas desired, The euttersfarehere illustrated'as eomprising'eutter carriers lhavi-g roller cutters13; but it will beunderstood that yany typejof ultimate cutter orcutting edge may be vused. Consequently, for "the purpose jof thisexpflanatongfthe 'elements-; f each Gutter, including the/cfl'tterCarrier,12` will be hereinafter lreferred t'o f "as all entity, endgmer'ely- `as Vthejoutter. WVith'n the tub' `l'a'r.`body.isan`internal-eutter, abutment and expandingzniandrel 15 Whiefh,fjin"the form Vhere illustratedhas fa; relatively large upper ypart 16jvWhi'e'hfis f'of. somewhat smaller diameterithanthe internal bore offthetubular body. Immediately be' f lovv rthis uplp'ejr larger 'part-ldisani abrupt diagonal Aexpadding shoulder V17 Athen' beloyv A thatshoulder Vis afcylfindrio mandrel ,part 1 8.; and 'below part 1 '8 themandrel `-has 'a `down-v extension '2O extends ondown throughthe .9

tubular body, and the @utter expanding- `spring'Qlis mountedinthe'lowerpartlof'the body around this mandrel 'extension 20,;tl-1'elower end olf the s pring fre`stin`g upongfsome suitable'sugpportlvvhi'eh J-is stationary Withreferen'eftothe-mandrel.For'instaneef, inthi'sy i partiular d 'esigrnl where the body isalso`statiionafr'y `with 'reference te 'the mandrel, the* www-@Ud Qfthe. Spring-may- 'S ll bi1 the @611er feawhich is sem-ned 'in the idy orwhich is supported upon the upper end of the tool joint pin 23 of thedrill bit 24 which is usually attached at the lower end of such anunderreamer. The upper end of spring 21 presses upwardly against acutter propeller plunger 24 which in turn presses upwardly on the lowerends of the Cutters. By inspection of thev drawings it will be seen thatthe inner mandrel contacting surfaces of the cutters are so formed thatwhen the cutters are moved upwardly they are also moved outwardly byinteraction with the mandrel. In such upward movement, in thisparticular typeof underreamer, the extreme lower ends of the cutters arenot moved outwardly; the eXtreme Vlower ends riding up the cylin- "dricmandrel extension part 21, to the position shown in Figure 2. Thus whenthe cutters ride up to the position of Figure 2, their lower ends notonly bear inwardly against'tapered portion 19 of the mandrel but thecutter wings 12a may also bear inwardly and circumferentially againsteach other. Figure 4 shows this circumferential bearing of the cutterwings when the cutters are contracted; and the same condition is true ofthe lower ends ofthe cutter wings when expanded as shown in Figure 2.The lower ends of the cutter wings as clearly shown in Figure 4 are ofsufficient thickness .(radial dimension) to fill the space between themandrel part and the wall of the tubular body; so that the lower ends ofthe cutters not only bear inwardly against the mandrel, but alsoinwardly, circumferentially, against each other and also outwardlyagainst the tubular wall of the body.

Also, in the contracted position of Figure 1, the upper ends of thecutter wings bear inwardly, circumferentially, against each other, as isshown in Figure 3. In this lower and contracted position of the cutters,their upper ends also bear inwardly against the part 18 of the cutterabutment mandrel, as shown in Figure 3.' But, in this contractedposition, the upper parts of the wings do not bear Y outwardly againstthe body wall as they must be spaced inwardly from the body wall farenough to allow for the outward expansive movements of the cutters whenthey move out to the position of Figure 2 where the upper ends of thecutter wings do bear outwardly againstthe body wall. Thus, in thecontracted cutter positions the disposition of the cutter wings 12a attheir upper ends, is such as is clearly shown Vin Figure 3 bearingcircumferentially against each other and inwardly against the abutmentmandrel. Y

There is, as l have said, an annular space between the upper largemandrel portion 16 and the body wall; and itis into this annular spacelthat the upper ends ofthe eutterwings move upwardly whenfthe' tool isexpanded. To hold the cutters down and thus to keep them from expanding,Iv insert int-o [this annular space a sleeve of such length that itsupper end may bear upwardly against the downwardly facing shoulder 3l onthe mandrel, and that its lower end bears downwardly against the upperends of the cutters. If the cutters merely were to be held down, thenthe lower end of this hold-down .sleeve could be plain and straight;but, in holding the cutters downI in contracted position, it is alsodesirable to hold them against any loose movement, both laterally andoutwardly. Thuslfprovide the lower end of the hold-down sleeve 30 withthree equidistantly spaced and downwardly extending lugs 32 which are ofsuch size and shape as to enter into and lill the spaces betweenadjacent cutters and between the cutter wings and the body wall. Thismay be seen most clearly by inspection of Figures l and 3. Thesedownwardly extending lugs thus fill the inter-cutter spaces within thebody, and prevent the cutters from having any loose motion laterally,and also positively prevent them from moving loosely outwardly, whilethey are held down in their contracted positions.

The upper ends of the cutters bear upwardly in what may be called thenotches 33 between adjacent lugs 32. rl'She upper ends of the cutters,where they engage upwardly against the sleeve 30, are square, asindicated at 40; although the upper inner corners are diagonal, as at41, to co-operate with the diagonal expanding face 17 of the mandrel.The lower end surfaces of the sleeve (the surfaces which form the upperedges of notches 33) are also square. Spring 21 presses the cutters upwith considerable force; so that the cutters are clamped longitudinallybetween the cutter propeller 24 at their lower ends and the sleeve- 30at their upper ends. This clamping may be in many cases sufficient tohold the cutters inwardly and thus lugs 32 might be dispensed with; butin the actual practice of reaming the cutters may at times be subjectedto tangential forces tending to work them outwardly, and the rise oflugs 32 positively prevents this.

Thus, by using the hold-down sleeve 30, the cutters of the underreamerare held down and prevented from being forcibly expanded. and at leastare frictionally clamped against outward movement; and using thehold-down sleeve having the described 'notched lower end, the cuttersare additionally held positively and rigidly against outward expansivemovement; and the whole structure is made solid Vand rigid in itscontracted position. Thus, the normally expansive underrearner istransformed easily into a plain non-expansive-reamer of great rigidityand strength.

In order to make the tool again an eX- pansive reamer, it is onlynecessary to remove the hold-down sleeve 30, and that, in thisparticular case, may easily be done by removing the internal mandrel,which, in this particular'design, is screw-threaded at 34 at its upperend into the upper endy of the body, When the hold-down sleeve 30 isremoved, I usually provide another shorter sleeve 50 which moves downwhen thecutters move down and which performs the function of closing theotherwise open upper ends of the cutter slots 11 and preventing entry ofmud and other matter which might clog the reamer. This protective sleeveis, however, not the particular subject-matter of this prest entapplication, but rather the subj ect-matter of my applicaion VSerialNo.12670,713, led March 10, 1928, allowed January 30, 1930, and nowPatent No.1,7 73,307: It is possible, however, to utilize this shorterprotection sleeve 50 as a part of the longer hold-down sleeve. Forinstance, by simply providing a shorter sleeve 30a, such as shown inFigure 5, formed at its `lower end with the notches 33 and the extensionlugs 32, and making the additive lengths of sleeve 50 and sleeve 30aequal to the total length of sleeve 30, the two sleeves 30a and V50 maybe used together. It

will be readily apparent how the internal mandrel may be removedupwardly from the body, 'and sleeve V30a slipped upwardly on the mandrelto a position immediately below sleeve 50, and then theV whole assemblyput back into the underreamer body. Then the two part sleeve'SOa, 50will act exactlyas does the'single integral sleeve 30.

It will be understood, as I have indicated, that the particular reamerdesign here set out is no limitation on my invention, but that thesleeve may be used in other specific reamer designs. For instance, whileI have described the mandrel and body as separate pieces they need notbe. Also, although I have described the body as fixed relative to theexpanding Y mandrel, that specific fact is not a necessary limitation onthe invention, and so neither is the form of the body or mandrel. Thefunction of the mandrel, in so far as my pres- A ent invention isconcerned, is to cause lateral expansion of the cutters on relativelongitudinal movement in one direction. The function of the body, ashere described, in so far as it has to dowith my present invention, ismerely to hold the cutters in around the inandrel; and it isimmaterialto this function whether the body moves longitudinally with i thecutters or remainsy stationary with the mandrel.

I claim: j t Y 1. In combination Vwith Han expansive reamer whichembodies an internal cutter Yexpanding mandrel, cutters surrounding themandrel and movable longitudinally thereon, andv abody confiningtheoutters aboutthe mandrel, the mandrel and cutters being so formedthat relative longitudinal movement between them in onedirection-.causes Aoutward expansive movement of the cutters; aremovable sleeve litting around the outward expansive movement 'oftheicutters aV removable sleeve bearing `longitudinally against a `shoulderprovided on tli'e1mandi'el, airdbearing longitudinally against Vthecutters to` prevent longitudinal movementVV of expansion. l 'i i i f, ,i

f `3. In 'combination` with Van expansive reamerwhich embodiesanVinternal cutter expanding'mandrel, cutters surrounding the 1 mandrel and`movable lbngitudinally thereon, and a jbodyV confining ithe cuttersabout the mandrehthe .mandrel andcutters being so formed that'rrelativelongitudinal movementlbetween them in one direction causes outwardexpansive movement of .the cutters; a removablesleevetitting around fthemandrel and bearing again'stthe cutterslongr.

tudinally to prevent'longitudinal expansiveY movement, said sleevehaving a circumferene `tially Vspaced'extensions which :enter "be- Ytween adjacent cutters and between thecutters and the'surroundingbody,to hold "the cutters rigidly. t Y j t v 4f. In combination. with iIan `expansive reamer which embodies an Vinternal cutter expandingmandrel, cutters'surrounding the mandrel an'dlmovable longitudinallythereon, and a body confining the cutters about they mandrel,Vthe-mandrel andI cutters being i so'formed that-relative longitudinalimovement betweentliem in `:one direction causes outward expansivemovement of the cutters; 'ag removable sleeve bearing f longitudinallyagainst ashoulder provided on 4the mandrel, and Vbe ariiigAlongitudinally against the cutters to ipreveii'tflongitudinal'.movementof expansion, said l.sleeve Vhaving l'circumferentially spacedextensions which "enter between adj acent "cutters iai'fd 'between 'the`cutters and i d the surrounding body, to hold the cutters rigidly.

:5. In an'v expansive reamer., the Icombinatio'nnof aninternallongitudinal cutter ex- Y. panding mandrel having a relativelylarge ,fi-4 cutter expanding part near one end and a relativelyrsmallpart nearerthe other end;

a"cu`tter lholding fbody annularly --spaced i l around the mandrelsofas' to leave,anannii-V larfspace between the body and the largerpartof the mandrehrcutters mounted in the body around. the mandrel andlongitudinally Y movable on the mandrel and adapted to ridelongitudinally onto thelarger mandrel parts and to `be expanded thereby,laterally extending wings on the cutters which, in the contractedposition of the cutters bear circumferentially against each other, and aremovable sleeve tting into and filling the annular space between thelarger part of the mandrel and the surrounding body to preventlongitudinal movement of the cutters onto the larger part ofthe mandrel.

6. In an expansive reamer, the combination of an internal longitudinalcutter expanding mandrel having a relatively large cutter expanding partnear one end and a relatively small part nearer the other end; a cutterholding body annularly spaced around the mandrel so as to leave anannular space between the body and the larger part of the mandrel,cutters mounted in the body around the mandrel and longitudinallymovable on the mandrel and adapted to ride longitudinally onto thelarger mandrel parts and to be expanded thereby, laterally extendingwings on the cutters which, in the expanded position of the cuttersenter into the annular space between the mandrel and body, and aremovable sleeve fitting into and filling the annular space between thelarger part of the mandrel and the surrounding body to preventlongitudinal movement of the cutters onto the larger part of themandrel.

7. In an expansive reamer, the combination of an internal longitudinallycutter expanding mandrel having a relatively large cutter expanding partnear one end and a relatively small part nearer the other end; a cutterholding body annularly spaced around said mandrel so as to leave anannular space between the body and the larger part of the mandrel,cutters mounted in the body around the mandrel and longitudinallymovable on the mandrel and adapted to ride longitudinally onto thelarger mandrel parts and to be expanded thereby, laterally extendingwings on the cutters which, in the contracted position of the cuttersbear circumferentially against each other and, at one end of the wings,bear outwardly against the body, and a removable sleeve iitting into andlling the annular space between the larger part of the mandrel and thesurrounding body to prevent longitudinal movement of the cutters ontothe larger part of the mandrel, said sleeve having circumferentiallyspaced longitudinal extensions which enter into spaces between adjacentcutters and be- {Jjwen the cutter wings and the surrounding In witnessthat I claim the foregoing I have hereunto subscribed my name this 31day of January, 1930.

JOHN GRANT.

